JP3082388B2 - Lithium secondary battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
And a lithium secondary battery in which the negative electrode is in contact,
In particular, Li as a positive electrode active material_xCoO_Two, Li_xNiO_Two
Or Li _xNi_1-yFe_yO_TwoUsing a material consisting of
And a lithium secondary battery.

[0002]

2. Description of the Related Art The development of a lithium secondary battery requires the development of an excellent positive electrode or negative electrode active material, and the search for such a material is being actively conducted today. For the negative electrode material, a lithium alloy is used from lithium metal. At the time of battery charging and discharging, an electrochemical reaction in which lithium ions in the electrolyte are reversibly changed to metallic lithium is used. Further, special carbon is used to transfer lithium between carbon layers. It is moving toward the use of reversible reactions.

[0003] On the other hand, as for the cathode material, similarly, a material in which lithium ions in an electrolyte enter and exit the active material has been used from those accompanied by a chemical change by electrochemical oxidation-reduction of the active material. . As the positive electrode material for the latter, sulfides such as titanium disulfide, niobium sulfide, and molybdenum sulfide, or interlayer compounds composed of tungsten oxide, molybdenum oxide, manganese dioxide, nickel oxide, cobalt oxide, and the like have been studied. When the battery is charged and discharged, a lithium ion in the electrolyte undergoes oxidation-reduction, and at the same time, a topochemical reaction occurs in which lithium moves in and out of the crystal layers of these layered compounds.

[0004] This trend in battery technology is due to the expectation that the charge / discharge cycle life of the battery will be improved because no chemical change of the substance is involved in the charge and discharge of the battery in the negative electrode and the positive electrode.

[0005] Therefore, in order to smoothly carry out this topochemical electrochemical reaction, a study on a crystal structure mainly using the above-mentioned various materials has been made. For example, nickel oxide,
Li _x Ni containing lithium in advance for cobalt oxide etc.
O ₂ and LiCoO ₂ are synthesized, and lithium is electrochemically extracted from this material to form a spinel structure or N 2.
An alternative to the aCl structure is being studied.

In synthesizing these materials, the following methods have conventionally been employed. 1) Metal nickel is immersed in LiOH heated and melted at 800 ° C., and oxidized in an oxygen atmosphere to produce Li.
A method of synthesizing NiO ₂ . 2) Nickel oxide (NiO) and lithium oxide (Li
₂ O) was mixed predetermined amounts, after a predetermined time at a temperature of 750 ° C the mixed material under a dry oxygen atmosphere, a method for synthesizing LiNiO ₂ was taken out to room temperature. 3) Nickel oxide (NiO) and lithium hydroxide (LiO)
H H ₂ O) was mixed in a ball mill at a predetermined amount, and the mixed material was reacted at a temperature of 700 ° C. for 1 hour in an air atmosphere, taken out to room temperature and ground for 1 hour. A method of synthesizing LiNiO ₂ by heating at 4 ° C. for 4 hours and taking it out of the furnace at room temperature.

It is difficult to obtain a single layer with the material synthesized by such a method, and not only hexagonal crystal but also cubic crystal is synthesized as the structure. Further, some of the cubic crystals are mixed with those having an order and those without the order.

As the positive electrode active material of the battery, a hexagonal layered compound is preferable. This layered structure serves as a so-called host, and a cubic close-packed layer of oxide ions is arranged in the 111 direction. It has a hexagonal rhombohedral structure in which layers of ions or nickel ions are present alternately, so that a large amount of lithium can be taken in. Contrary to this, in the cubic system, it is difficult for lithium ions to enter the crystal.If the synthesized material contains a crystal structure other than hexagonal, the amount of lithium inserted is reduced. , Resulting in a low energy density. Therefore, it is conceivable to use such a hexagonal material as the positive electrode active material of the battery.

[0009]

SUMMARY OF THE INVENTION Lithium nickel oxide
When using as a positive electrode active material,
For example, a predetermined amount of nickel oxide and lithium hydroxide are mixed
And react by heating_xNiO_TwoOr Li
_xNi_TwoO_FourAre synthesized. Li from these synthesized materials
Is electrochemically extracted to form a NaCl-type Li
_xNiO_TwoAnd Li _xNi_TwoO_FourSpinel structure
You.

As a positive electrode active material of a lithium secondary battery, a hexagonal structure Li _x NiO ₂ is capable of allowing lithium ions to enter and leave the most, ie, in order to improve the energy density, a hexagonal structure is required. It is important to easily synthesize only those having a structure in developing an excellent energy density battery. Furthermore, when a sulfide-based lithium ion conductive solid electrolyte is used as the electrolyte, the decomposition voltage is 5 V or more, and the electrolyte using an organic solvent is about 4.1 V, which is much higher than that. It is preferable to make the potential at which ions are taken in and out as high as possible in order to develop a high-voltage and high-energy density battery. As a material meeting such a purpose, it is desired to develop a material capable of easily allowing lithium ions to enter and exit while maintaining a hexagonal structure, and to propose a lithium secondary battery composed of such a material.

An object of the present invention is to provide a lithium secondary battery that meets such a demand.

[0012]

The lithium secondary battery of the present invention
The pond has a positive electrode and a negative electrode in contact with a lithium ion conductive electrolyte.
Has a hexagonal crystal structure
Li_xCoO_Two, Li _xNiO_TwoOr Li_xNi
_1-yFe_yO_TwoAs a positive electrode active material.

When the positive electrode active material is Li_xCoO_TwoIf
Lithium peroxide (Li_TwoO_Two) And oxidation
Using cobalt (CoO), the cathode active material is Li_xNiO
_TwoIn the case of, lithium peroxide (Li
_TwoO_Two) And nickel oxide (NiO)
Is Li_xNi_1-yFe_yO_TwoIn the case of
Lithium peroxide (Li_TwoO_Two) And nickel oxide (N
iO) and iron oxide (Fe _TwoO_Three) And use these materials
Pulverize and mix well in an active atmosphere and then Li _xCoO
_Two800 ° C or less for Li_xNiO_Two, Li_xN
i_1-yFe_yO _TwoIn case of heating at 750 ° C or less
After the solid phase reaction, the heating temperature
From the room temperature to below room temperature
To obtain a hexagonal material,
Used as a positive electrode active material for ponds.

Further, as a lithium ion conductive electrolyte, Li ₂ S—SiS ₂ , Li ₂ S—GeS ₂ , Li ₂
SP ₂ S ₅ , Li ₂ SB ₂ S ₃ -based sulfides and compounds containing these sulfides, for example, Li ₂ S-SiS ₂
By using a lithium ion conductive solid electrolyte such as —Li ₃ PO ₄ or Li ₂ S—SiS ₂ —Li ₂ SO _{4, the} charge / discharge effect can be enhanced.

[0015]

[Function] Li _x used as a positive electrode active material for lithium batteries
CoO ₂ , Li _x NiO ₂ or Li _x Ni _1-y Fe _y O ₂
As a result of studying the method of synthesizing, it is possible to easily adjust the composition stoichiometrically by using lithium peroxide as a synthesis starting material, and to obtain Li _x CoO ₂ , Li _{x having} a desired composition. NiO ₂ or Li _x Ni _1-y
Fe _y O ₂ is obtained. Therefore, when a lithium battery is configured, the one having the largest energy efficiency can be selected. Furthermore, in the case of Li _x CoO _2, the temperature is 800 ° C. or less, and in the case of Li _x NiO ₂ and Li _x Ni _1-y Fe _y O ₂ , the temperature is 75 ° C.
By rapidly quenching from a synthesis reaction temperature of 0 ° C. or less, the crystal structure can be made hexagonal. In addition, Li _x N
In the case of i _1-y Fe _y O ₂ , the Fe content is 0.3
In the following, that is, when y < 0.3 , hexagonal crystal is obtained, and when y < 0.3 , cubic crystal is obtained, which is not preferable as a battery material.

[0016]

EXAMPLE First, as a positive electrode active material of a lithium battery, L was used.
iNiO ₂ and LiNi _1-y Fe _y O ₂ (where y
Is the content of Fe, and indicates that a part of Ni is substituted by Fe. We examined what crystal structures can be obtained for the various positive electrode active materials according to the synthesis conditions.

FIG. 1 shows a phase diagram of the obtained LiNi _1-y Fe _y O ₂ . The horizontal axis indicates the Fe content, and the vertical axis indicates the temperature at which rapid cooling is started. In obtaining this phase diagram, each material is composed of lithium peroxide (Li ₂ O ₂ ), nickel oxide (Ni
O) Further, if necessary, iron oxide (Fe ₂ O ₃ ) is mixed under a stoichiometrically inert atmosphere so as to have a composition of each sample, and then reacted at 850 ° C. for 40 hours in a dry oxygen atmosphere. The material was charged into liquid nitrogen from each temperature (vertical axis) shown in FIG. 1 and rapidly cooled. Further, the crystal structure obtained by rapid cooling from 750 ° C. using a twin roller at room temperature is shown below. In the figure, ○ indicates a cubic crystal having an order, △ indicates a cubic crystal lacking the order, and X indicates a hexagonal structure.

As is evident from FIG. 1, one containing no Fe, that is, LiNiO ₂ is reacted at a temperature of 750 ° C. or less, and then rapidly cooled from the temperature to a temperature of less than room temperature to form a hexagonal one. It is clear that at higher temperatures, it becomes cubic. Also, a part of Ni is changed to F
It was found that the LiNi _1-y Fe _y O ₂ substituted with e became hexagonal when the Fe content y was less than 0.3 and cubic when it was 0.3 or more.

On the other hand, LiCoO ₂ was synthesized in the same manner. That is, lithium peroxide (Li ₂ O ₂ )
0.5 mol and 1 mol of cobalt oxide (CoO) are pulverized and mixed in an inert atmosphere, reacted at 850 ° C. for 40 hours, and then dried at 300 ° C. and 400 ° C. in a dry oxygen atmosphere.
C, 500 ° C, 600 ° C, 700 ° C, 750 °
C, 800 ° C., and 850 ° C., each sample was put into liquid nitrogen and rapidly quenched to obtain various LiCoO
₂ was synthesized. As a result, it was found that a hexagonal crystal was obtained by rapidly quenching at a reaction temperature of 800 ° C. or lower, and a cubic crystal was obtained at a higher temperature.

Next, a lithium battery was constructed using the various materials thus synthesized, and the characteristics thereof were examined.

Hereinafter, a lithium battery using the positive electrode active material will be described in detail with reference to examples.

Example 1 Li prepared by the rapid quenching method
A mixture was prepared in advance by sufficiently mixing CoO ₂ as a positive electrode active material, 10% of carbon as a conductive material, and 3% of Teflon powder as a binder, and the mixture was formed mainly on a current collector network made of stainless steel. Disk shape (thickness 0.5
mm, diameter 1 cm) to form a positive electrode. As a negative electrode, a graphite negative electrode having the same shape as the positive electrode was prepared using a mixture in which 3% of Teflon powder was mixed with graphite powder as a binder. A coin-type battery as shown in FIG. 2 was produced using the electrodes thus produced. In the figure, 1 is a positive electrode, 2 is a negative electrode, 3 is a separator made of a nonwoven fabric made of polypropylene, 4 is an electrolyte, and the electrolyte 4 is a solution obtained by dissolving LiPF ₆ as a solute in a mixed solvent of propylene carbonate and dimethoxyethane. Was used. 5 is a stainless steel case, 6
Denotes an upper cover, 7 denotes a positive electrode ring, and 8 denotes packing. FIG. 3 shows a charge / discharge curve of this battery.
For comparison, the L prepared by the method of the conventional method (1) was used.
The broken line shows the charge / discharge characteristics (charge / discharge current: A = 0.2 mA / cm) of the battery using iCoO ₂ as the positive electrode active material. A battery using an active material manufactured by a conventional method has a capacity of about 0.5 mA.
h, whereas the battery according to the invention exhibits a charge / discharge capacity of about 0.6 mAh,
0.68F per unit cell, clearly indicating that the battery performance of the present invention is improved. This is considered to be because the crystal structure of LiCoO ₂ , which is a battery positive electrode active material prepared by a conventional method, includes a material other than hexagonal, for example, a cubic crystal.

(Example 2) A coin-type battery was fabricated in exactly the same manner as in Example 1 except that the cathode active material LiCoO ₂ used as the electrolyte in Example 1 was replaced with LiNiO ₂ and lithium was used as the negative electrode.

The charging / discharging behavior of the battery and the charging / discharging behavior of the battery prepared using LiNiO ₂ synthesized by the conventional method (1) were examined in the same manner as in Example 1, and the results are shown in FIG. (〇): Battery according to the present invention, □: Battery charge / discharge results by the conventional method are shown).

The charge / discharge capacity is about 1 mA at about 0.9 mAh.
A capacity of 0.78 F per 1 was obtained, and it can be clearly seen that the battery of the present invention had an improved capacity of about 0.1 mAh as compared with the conventional battery. This is presumably because, as in Example 1, the crystal structure of LiNiO ₂ , which is a battery positive electrode active material, prepared by a conventional method includes a material other than hexagonal, for example, cubic.

(Example 3) A coin-type battery was produced in exactly the same manner as in Example 2 except that the cathode active material LiNiO ₂ used in Example 2 was replaced with LiNi _1-y Fe _y O ₂ .

The charging / discharging behavior of this battery is shown by a solid line.
LiNiO used in Example 2_TwoOf batteries created using
The movement is shown by a broken line in FIG. In addition, when the content y of Fe differs,
The battery characteristics of each material are also shown (in the figure, ○: L
iNiO_Two, △ mark: LiNi _-0.9Fe_0.1O_Two, ×: L
iNi_0.8Fe_0.2O_TwoAre shown).

Obviously, the discharge capacity decreases as the Fe content increases, and the charge / discharge voltage increases accordingly. This seems to indicate that the higher charging voltage is accompanied by decomposition of the electrolyte during charging. That is, Ni of the positive electrode active material LiNiO ₂
It has been found that by partially replacing Fe with Fe, the charge / discharge voltage temporarily increases, and it can be said that the presence of Fe contributes to increasing the voltage of the battery.

(Example 4) Li ₂ S-Si as an electrolyte
An all-solid lithium battery was constructed using a lithium solid electrolyte made of S ₂ —Li ₃ PO ₄ , using LiNi _0.8 Fe _0.2 O ₂ as a positive electrode active material, and using a lithium sheet as a negative electrode. The lithium solid electrolyte used here was first pulverized and mixed with Li ₂ S—SiS ₂ in a dry atmosphere so that the molar ratio of the composition was 0.61: 0.39, and then the mixture was charged into a carbon crucible. After a melting reaction at a temperature of 950 ° C. in an inert atmosphere, the glass was immersed in liquid nitrogen and rapidly cooled to form a glass made of Li ₂ S—SiS ₂ . Thereafter, the glass was crushed, 3 mol of lithium phosphate was added to the glass, and the mixture was sufficiently mixed under a dry atmosphere.
The mixture was heated and reacted at C. After that, it is immersed in liquid nitrogen and rapidly cooled to obtain glassy Li ₂ S—SiS ₂ —Li ₃ PO
_Four lithium solid electrolytes were prepared. The ionic conductivity of the solid electrolyte thus obtained was 7 × 10 ⁻⁴ S / cm, and the decomposition voltage was 5 V or more.

In manufacturing an all-solid lithium battery element,
In FIG. 6, a pellet-shaped positive electrode having a shape indicated by 9 was produced. The positive electrode 9 is prepared by press-molding a material obtained by sufficiently mixing an active material, a solid electrolyte and carbon as a conductive material at a ratio of 1: 0.8: 0.2 with a press machine in advance. In contact with the prepared pellet-shaped positive electrode 9, the solid electrolyte was further uniformly placed in a press mold so as to form a pellet having a thickness of 0.2 mm, and was subjected to pressure molding to form the positive electrode 9 as shown in 10 in FIG. And integrated. An all-solid lithium battery element shown in FIG. 6 was produced by further pressing the negative electrode 11 made of lithium metal on the electrolyte 10.
Using the battery case components indicated by 5, 6, 7, and 8 in FIG. 2 for the element thus manufactured, an all solid lithium battery having a battery shape as shown in FIG. 2 in appearance was manufactured.

FIG. 7 shows the charging / discharging behavior of this battery at a constant current (20 μA / cm ² ). In the figure, positive electrode active materials having different Fe contents (in the figure, ○: LiNiO ₂ , Δ:
LiNi _0.9 Fe _0.1 O ₂ , ×: LiNi _0.8 Fe _0.2
O ₂ ) are also shown.

Unlike Example 3, the discharge voltage is high, and tends to increase as the Fe content increases. Further, the discharge capacity was almost the same as that of any battery. This is when the organic electrolyte discharges,
It is considered that the charging efficiency was lowered due to the electrolysis of the electrolyte, but the charging efficiency at the time of charging was improved by employing a solid electrolyte having a high decomposition voltage as the electrolyte.

Further, after charging the battery and stopping the charging at 4.6 V, the battery was stored in a high-temperature layer at 60 ° C. for 500 hours.
After that, when discharging at a constant current of ²⁰ μA / cm ² ,
The discharge capacity was almost the same as the discharge characteristics immediately after charging.

Example 5 The lithium ion conductive solid electrolyte (Li ₂ S—SiS ₂ —Li ₃ P) used in Example 4
A whole lithium battery was produced in the same manner as in Example 4 except that Li ₂ S—SiS ₂ —Li ₂ SO ₄ was used instead of O ₄ ), and its charge / discharge characteristics and storage characteristics were examined. As a result, the same result as in Example 4 was obtained.

Example 6 The lithium ion conductive solid electrolyte (Li ₂ S—SiS ₂ —Li ₃ P) used in Example 4 was used.
An all-solid-state lithium battery was fabricated in the same manner as in Example 4 except that Li ₂ S—SiS ₂ —LiI was used instead of O ₄ ), and its charge / discharge characteristics and storage characteristics were examined. As a result, the same discharge characteristics as in Example 4 were obtained for the discharge characteristics immediately after charging, but the storage characteristics showed a decrease in the discharge voltage of about 350 mV, and the discharge capacity also dropped to about 70%. This is because the lithium anode and the solid electrolyte used in this example chemically react during storage, a high resistor is formed at the interface, and the internal resistance of the entire battery is increased. Conceivable.

Example 7 The lithium ion conductive solid electrolyte (Li ₂ S—SiS ₂ —Li ₃ P) used in Example 4
An all-solid lithium battery was prepared in the same manner as in Example 4 except that Li ₂ S—SiS ₂ —B ₂ S ₃ was used instead of O ₄ ), and its charge / discharge characteristics and storage characteristics were examined. As a result, the discharge characteristics immediately after charging were the same as those in Example 4, but the storage characteristics showed a decrease in the discharge voltage of about 180 mV, and the discharge capacity was reduced to about 75%. Was. This is because, similarly to Example 6, the lithium anode and the solid electrolyte used in this example chemically react during storage to form a high resistor at the interface and increase the internal resistance of the entire battery. It is considered to be due to this.

Example 8 The lithium ion conductive solid electrolyte (Li ₂ S—SiS ₂ —Li ₃ P) used in Example 4
An all-solid lithium battery was fabricated in the same manner as in Example 4 except that Li ₂ S—SiS ₂ —P ₂ S ₅ was used instead of O ₄ ), and its charge / discharge characteristics and storage characteristics were examined. As a result, the same discharge characteristics as in Example 4 were obtained for the discharge characteristics immediately after charging. However, regarding the storage characteristics, the discharge voltage was reduced by about 320 mV, and the discharge capacity was further reduced to about 65%. Was. This is because, similarly to Example 6, the lithium anode and the solid electrolyte used in this example chemically react during storage to form a high resistor at the interface and increase the internal resistance of the entire battery. It is considered to be due to this.

[0038]

According to the present invention, hexagonal Li _x CoO ₂ and Li _x NiO
_{By using 2} or Li _x Ni _1-y Fe _y O ₂ as a positive electrode active material of a lithium secondary battery, a battery having a large discharge capacity becomes possible, and in particular, when the Fe content is 0 or more,
When it is less than 0.3, a battery having a high charge / discharge voltage can be obtained. At this time, in order to improve the charge / discharge efficiency, the use of the lithium ion conductive solid electrolyte as the electrolyte allows the positive electrode active material of the present battery system to work more effectively.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a rapid quenching start temperature of LiNi _1-y Fe _y O ₂ and a synthesized crystal phase.

FIG. 2 is a sectional view of a lithium secondary battery according to one embodiment of the present invention.

FIG. 3 is a charge / discharge characteristic diagram of a lithium secondary battery in one example of the present invention. (A) Charging characteristic diagram (b) Discharging characteristic diagram

FIG. 4 is a charge / discharge characteristic diagram of a lithium secondary battery in one example of the present invention. (A) Charging characteristic diagram (b) Discharging characteristic diagram

FIG. 5 is a charge / discharge characteristic diagram of a lithium secondary battery in one example of the present invention. (A) Charging characteristic diagram (b) Discharging characteristic diagram

FIG. 6 is a schematic structural diagram of an all-solid-state lithium battery element according to one embodiment of the present invention.

FIG. 7 is a charge / discharge characteristic diagram of the all-solid-state lithium battery in one embodiment of the present invention. (A) Charging characteristic diagram (b) Discharging characteristic diagram

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode 2 Negative electrode 3 Separator 4 Electrolyte 5 Case 6 Upper lid 7 Positive electrode ring 8 Packing 9 Positive electrode 10 Solid electrolyte 11 Negative electrode

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-127454 (JP, A) JP-A-1-134876 (JP, A) US Pat. No. 4,302,518 (US, A) US Pat. (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 4/02-4/04 H01M 4/58 H01M 10/40

Claims (8)

(57) [Claims] (1) a positive electrode and a negative electrode are formed by lithium ion conductive electrolysis;
In a lithium secondary battery in contact with a material , the positive electrode active materials are lithium peroxide (Li ₂ O ₂ ) and cobalt oxide (C
oO) is mixed and reacted at a temperature of 800 ° C. or less, and thereafter, a hexagonal crystal obtained by quenching from this temperature is obtained.
Features and to Brighter Chiu <br/> arm secondary battery that is Li _x CoO _2, having the structure. 2. The method according to claim 1, wherein the positive electrode and the negative electrode are lithium ion conductive electrolysis.
In a lithium secondary battery in contact with a material , the positive electrode active materials are lithium peroxide (Li ₂ O ₂ ) and nickel oxide (N
iO) is mixed and reacted at a temperature of 750 ° C. or lower, and thereafter, a hexagonal crystal obtained by quenching from that temperature is obtained.
Features and to Brighter Ji <br/> um secondary battery that is Li _x NiO ₂ having a crystal structure. 3. The method according to claim 1, wherein the positive electrode and the negative electrode are lithium ion conductive electrolysis.
In a lithium secondary battery in contact with a material , the positive electrode active materials are lithium peroxide (Li ₂ O ₂ ) and nickel oxide (N
Li _x Ni having a hexagonal crystal structure obtained by mixing iO) and iron oxide (Fe ₂ O ₃ ) and reacting at a temperature of 750 ° C. or lower, and then rapidly cooling from the temperature. _1-y Fe
features and be lapis lazuli lithium secondary battery that is _y O _2. 4. The y value of the Li _x Ni _1-y Fe _y O ₂ is y <y
The lithium secondary battery according to claim 3 , wherein the value is 0.3 . 5. a lithium ion conductive solid electrolyte as the lithium ion conductive electrolyte, a lithium secondary battery according to any one of claims 1 to 4, characterized in that constructed on solid lithium batteries. 6. The lithium ion conductive solid electrolyte is composed of Li ₂ S—SiS ₂ , Li ₂ S—GeS ₂ , and Li ₂ S—P ₂ S.
_5, lithium according to any one of claims 1 to 5, characterized in that Li ₂ S-B ₂ S ₃ type of sulfide and a sulfide-based lithium ion conductor is selected from compounds containing these sulphides Rechargeable battery. 7. A lithium ion conductive electrolysis for a positive electrode and a negative electrode.
In a lithium secondary battery in contact with
Li _x CoO ₂ , Li _x NiO ₂ or L having a crystalline structure
The _{i x Ni 1-y Fe y} O 2 as the positive electrode active material, a lithium-ion
Li ₂ S-SiS ₂ , Li ₂ S-Ge as conductive electrolyte
S ₂ , Li ₂ SB ₂ S ₃ -based sulfides and these sulfides
Lithium Ion Conductivity Selected from Containing Compounds
The fact that an all-solid lithium battery was constructed using a solid electrolyte
Characteristic lithium secondary battery. 8. The lithium ion conductive solid electrolyte is Li ₂ S—SiS ₂ —Li ₃ PO ₄ , Li ₂ S—SiS ₂ —L
The lithium secondary battery <br/> claim 6 or 7, characterized in that a i ₂ SO _4.